Jul 11

Minimizing Polyhedra

article on minimizing polyhedra


Jun 07


KaleidoTile is a colorful program for investigating Tilings, Symmetry, and Polyhedra.  I remember seeing it many years ago. I’m glad to see that Jeff Weeks is continuing to update it.  FREE download.


Oct 30

Ball of Whacks

Update: I turned this into a full page:  Top 8 Interesting Things to Know about the Rhombic Triacontahedron

Ball of Whacks is a geometry toy. (Available online and in toy stores that sell cool stuff.)whacks

It is a rhombic triacontahedron.  Each of the 30 rhombic faces are golden, in that the ratio of the diagonals is the Golden Ratio.

Good stuff at https://en.wikipedia.org/wiki/Rhombic_triacontahedron

It is the dual of the Icosidodecahedron (which is Archimedean), which is the Hoberman Sphere.

I have a light in my office (which was a gift from my kids) which is the rhombic triacontahedron.


Oct 25

Prince Rupert’s cube

Cut a hole in one cube so that a cube of the same size (actually one slightly bigger!) can pas through.


Jun 20

Article: 5 Reasons Why Origami Improves Students’ Skills

5 Reasons Why Origami Improves Students’ Skills


Jun 08

I’ll be doing a Beauty of Three Dimensional Polyhedra Workshop

Beauty of Three Dimensional Polyhedra Workshop (in Celebration of the MAA’s Centennial)

MathFest at Washington, DC. Friday, August 7, 2015, 1:00-2:20 p.m., Maryland C

Description: I have long been fascinated by the Platonic and Archimedean solids and their mathematical beauty. In this workshop I will demonstrate, and we will work with, a variety of materials I’ve come across over the years for building polyhedra. For example, we’ll build with coffee stirrers (really cheap, less than 10 cents for the icosahedron), origami (about  25 cents for the Buckyball), and retail manipulatives (a few dollars for the truncated tetrahedron). We will also look at some online tools for exploring (and enjoying) the Platonic and Archimedean solids and their mathematical relationships and properties. These dynamic tools are useful is seeing how, for example, the snub icosidodecahedron is formed.  (Attendees are encouraged to bring a laptop or device to the workshop.) Included will be how the icosahedron
(this is the MAA!) can be built using three golden rectangles.

Organizer: James R. Olsen, Western Illinois University

MathFest info / Workshop info